Drag & drop not working

I started the pc and began to work on a SSIS project, surprise: drag & drop from the toolbox not working; trying to move a file in the Windows Explorer, the same.I tried to verify the mouse installation, properties in Control Panel: nothing.The solution is strange, but it works: In Windows Explorer, click a file with the left mouse button and keep the button pressed, then press the Escape key; drag & drop is back.